1. Field of the Invention
The present invention relates to a method for forming decorative creases or wrinkles in a trim cover assembly for an automotive seat, and an automotive seat with the trim cover assembly having those decorative creases or wrinkles formed therein.
2. Description of Prior Art
There has been known an automotive seat on which is affixed such upholstery as a foam cushion member and a trim cover assembly covering the foam cushion member, with some decorative creases formed in the trim cover assembly, for improving the aesthetic appearance of the seat. FIG. 1 shows a conventional automotive seat which comprises a seat back (SB) and a seat cushion (SC), each being covered with a trim cover assembly, needless to mention, and the central seating cover sections (10)(10) of the respective trim cover assemblies of the seat back (SB) and seat cushion (SC) are shown to be formed with some plural rows of decorative creases (X')(Y') therein.
In this illustration, regardless of both seat back (SB) and seat cushion (SC), the trim cover assembly central cover section (10) is formed by sewing together three separate strips of covering members (10A)(10B)(10C). But, before forming such central cover section (10), the three separate covering members (10A)(10B)(10C) are each gathered and sewn at its both lateral sides by means of a sewing machine designed therefor, as can be seen from FIG. 1, so as to create plural decorative creases (X')(Y') in both sides of each covering member.
That gathering sewing operation itself is known, by use of a particular conventional sewing machine (M) shown in FIG. 3, which will therefore not be explained in details.
Briefly stated, however, in the conventional state of art, as indicated by the arrow 1 in FIG. 1, one lateral end portion of each covering member (10A, 10B or 10C) is firstly gathered and sewn by the sewing machine (M) in one direction (i.e. in the downward direction as viewed from FIG. 1), and then, as understandable from FIG. 3, the gathered parts (1a, 1a, . . . ) of the covering member (10A, 10B or 10C) are pressed and folded one after another on the surface thereof by means of the retainer member (M1) of sewing machine (M), and sewn in the sewing direction (S), to thereby effect sewing in a gathered fashion.
It is noted here that in FIG. 3, the arrow (S) stands for a sewing direction of the machine (M) corresponding to that of the arrows 1/ and 2/ in FIG. 1, and the arrow (F) stands for a feeding direction of the same machine (M) for feeding the covering member.
As the gathered parts (1a) are folded and sewn adjacent to and along the lateral end of covering member (10A, 10B or 10C), the resultant creases (X') tend to develop themselves outwards in a generally rearwardly slant fashion in reference to a seam line along the sewing direction 1/ . After completing this first sewing, another lateral end portion of the covering member (10A, 10B or 10C) is subject to the same gathering sewing in another direction 2/ (i.e. in the upward direction as viewed from FIG. 1) opposite to that of the foregoing first sewing operation. As a result, such second sewing produces the creases (Y') which are developed in a generally rearwardly slant fashion in reference to that another sewing direction 2/ . Thus, an apparent difference arises in the slant developing direction between those two decorative creases (X')(Y') as seen in FIG. 2, due to the different sewing directions 1/ and 2/ above.
With the same sewing steps described above, each of other remaining two covering members (10B)(10C) are formed with the similar two mutually oppositely oriented decorative creases (X')(Y').
Finally, all the three covering members (10A)(10B)(10C) are sewn together at their corresponding both lateral ends to provide a one unit of central seating cover section (10), which is further affixed by means of anchoring member (not shown) upon the corresponding area of cushion member (not shown), as in FIG. 1.
However, the resultant central seating cover section (10), which forms a part of trim cover assembly for the seat shown in FIG. 1, represents all of the decorative creases (X')(Y') to be slant in the same direction, per each of vertical rows of creases which are defined at the sewn jointed portions among the three covering members (10A)(10B)(10C) where the adjoining lateral ends of those covering members with the creases (X')(Y') are sewn and jointed with one another. This has been found very objectionable for the decorative creases, and impaired the aesthetic appearance of the trim cover assembly affixed over the seat.